Not Hitchcock's best, but the script is fantastic and the actors are terrific. It's fairly obvious that it's based on a play, as there's really only one setting, and not much room for Hitch's camera to work its magic, but he does great work anyway and the story is more than enough to keep the film riveting. It's hard to keep up, but if you do, it's well worth it at the end. Grace Kelly is as beautiful as ever and Ray Milland gives a terrifically villainous performance without resorting to overacting. Could be Hitch's most underrated work.